“The worst possible thing you can do with Donald Trump is meet with him in person and try to play him,” Graham lectured Kim in a statement a day after Trump shocked the world by agreeing to meet with the North Korean leader. “If you do that it will be the end of you — and your regime.”

White House press secretary Sarah Sanders underscored that message, noting that “Senator Graham has been on the other side of that and certainly knows the capabilities and determination of President Trump.”

On the surface, this was about nuclear diplomacy. But the obvious subtext, as it often is with Trump, was golf.

Unmistakably, at least to me, Graham was basing his remarks on his own experience last October, when he met with Trump in person, at Trump National Golf Club in Virginia, and tried to play him. In 18 holes, the president finished off the job of demolishing his old rival, a battle that began in the 2016 presidential campaign (Graham didn’t even make it until the end of 2015).

According to the definitive account of the match, on Golf.com, he ended up owing Trump $30 on their wager, of which he had only $5 on him at the time. Some observers have suggested that Trump allowed Graham to pay off the remainder of the bet with his soul. A few months earlier, Graham had called out Trump over his response to the Charlottesville neo-Nazi rally, in remarks that Trump called “a disgusting lie,” but shortly after they began golfing together, Graham reported seeing signs of Trump “growing into the job,” and remade himself “from one of Trump’s fiercest critics to his chief congressional translator.”

Hence, the warning to Kim: If you don’t want the fire and fury of Trump’s 250-yard drives unleashed on you, don’t play him.

But does Kim even golf?

Hard to know for sure. He doesn’t give the appearance of athleticism, but golf is a sport in which participants spend most of a match sitting down in a cart. And he has the genes, according to the North Korean state media, which reported that the first time his late father, Kim Jong Il, picked up a golf club, he scored five holes in one, for an 18-hole score of 34, about the equivalent of hitting 120 home runs in a season. It’s not known if the incumbent Kim has ventured on to Pyongyang’s only course, which seems to cater to a few dozen Chinese tourists a day. But he does seem to have an interest in miniature golf, which suggests he might be able to hold his own, at least, on the greens.

Neither Trump nor anyone else has ever claimed to have matched the late Kim’s 38-under-par round. But the president is, by all the evidence, a very good golfer, as he is prone to pointing out himself:

Just won The Club Championship at Trump International Golf Club in Palm Beach-lots of very good golfers-never easy to win a C.C.

Graham thinks so, too, tweeting rapturously: “President Trump shot a 73 in windy and wet conditions!” That was the same President Trump who insisted that his inaugural crowd was the largest in history. As Golf.com noted, “The senator’s claimed score for Trump is patently unbelievable to many golfers. A score of 84 would seem plausible. … A 73, from a 71-year-old who plays often for a president but infrequently for a low-handicap golfer? Unlikely, to say the least.”

But that’s not to say he isn’t good. Alan Shipnuck’s definitive analysis of Trump’s game agrees that the president “is surprisingly limber for a portly man of 6’ 2″, and his good eye-hand coordination shows through in all aspects of his play, but especially in his ability to hole putts.”

Others, including the New Yorker’s David Owen, have written about Trump’s uncanny skill in putting, which makes sense to me. Hitting the ball into the hole from 4 feet away is hard precisely because it seems like it should be easy. On the greens, the enemies of performance are doubt, self-consciousness and overthinking, things Trump has never been suspected of harboring. Trump’s blithe disregard for the risks of being caught in a lie suggests he is unlikely to succumb to a case of the nerves.

In fact, he used putting to illustrate why he thinks arming teachers to shoot back at assailants could work: “I want highly trained people that have a natural talent, like hitting a baseball or hitting a golf ball or putting. How come some people always make the four-footer, and some people, under pressure, can’t even take their club back?”

I can think of a few other reasons why golf is Trump’s game. It is a sport that ranks about midway between handball and yachting on the scale of expense, which he casts as a virtue, as he explained to Fortune magazine in 2015: “Let golf be elitist. When I say ‘aspire,’ that’s a positive word. Let people work hard and aspire to some day be able to play golf. To afford to play it.”

Golf is also a venue for the kind of socializing Trump likes to do, with other rich businessmen and public officials — although we can’t say for certain how much this goes on, since the White House mostly doesn’t talk about Trump’s time golfing. (He famously denounced Barack Obama as a slacker for spending time on the golf course, and promised to work harder, but after one year as president, according to Politifact, Trump had played a minimum of 44 rounds of golf, compared to 29 over the same period for Obama.) And there are other kinds of social contacts one can make while golfing. According to an account Stormy Daniels gave Slate’s Jacob Weisberg, Trump’s first encounter with the porn actress took place at a celebrity golf tournament in Las Vegas.

And golf, almost unique among athletic pursuits, has no referees, umpires or judges, except at the professional championship level. Scoring is on the honor system, which gives a considerable advantage to anyone willing to grab an edge or bend the rules. Owen wrote about a match he played with Trump at his club in West Palm Beach, and after the article appeared, Trump called him to complain that he didn’t write that Trump had shot an extremely impressive 71 that day.

“I hadn’t written that because he hadn’t shot 71. We hadn’t been playing for score, and we had given each other putts and taken other friendly liberties—as golfers inevitably do when they’re just fooling around. I said something to that effect in the politest way I could think of, but he wasn’t mollified.”

As Shipnuck wrote, “Trump will sometimes respond to a shot he duffed by simply playing a second ball and carrying on as if the first shot never happened. In the parlance of the game, Trump takes floating mulligans, usually more than one during a round. Because of them it is impossible to say what he has actually shot on any given day.”

Trump has been taking mulligans his whole life; he just got one from evangelicals on his marriage vows, as Family Research Council president Tony Perkins told CNN, apropos of whatever went on with porn star Stormy Daniels: “Yes, evangelicals, conservatives, they gave him a mulligan. They let him have a do-over. They said we’ll start afresh with you and we’ll give you a second chance.” Having impulsively announced tariffs on steel and aluminum last week, Trump seems to be seeking one there, too, although his position is so incoherent it’s hard to tell. Dissatisfied with the deal President Obama struck with Iran, he’s asking for a do-over on that.

But nuclear diplomacy is a trickier game than golf.

We don’t know what games Kim plays. The national board game of Korea is baduk, known in the United States as “go.” It is by some accounts harder to master than chess, and top players are said to think dozens of moves ahead. You can no more imagine Trump sitting down to it than running a four-minute mile. He plays a sport in which the apex of achievement is the hole in one, the dramatic game-changing swing, and that seems to be what he is hoping for in rushing into a summit for which, most analysts agree, he is woefully unprepared. If his first shot goes into the water, will Kim give him a mulligan?